OZ Minerals continues to work towards effective stewardship of natural resources by minimising our environmental footprint and by using energy and other raw materials efficiently. All exploration and the design, construction, operation, rehabilitation and closure of mining facilities and associated group offices are guided by our OZ Minerals Energy and Greenhouse Gas Management Standard.
We continued our participation in the Carbon Disclosure Project and the Australian Government Energy Efficiency Opportunities (EEO) program. A requirement of the EEO program is to have two years of operational data to allow for an adequate assessment of an operations energy use. Prominent Hill’s first Energy Efficiency Assessment under the EEO program will be completed by 30 June 2011.
During the reporting period, a baseline energy assessment and efficiency project was carried out at the Prominent Hill operation. The aim of this project was to provide a comprehensive understanding of energy use and potential key areas of improvement for energy management.
Our work to identify cost effective energy use savings through the EEO program will remain a key component of the Group’s energy and greenhouse gas management.
Energy consumption
The consumption of energy has operating costs and environmental implications for the business. Impacts of energy consumption, such as the release of greenhouse gas emissions and air pollutants, can in part be minimised through improved energy use efficiency. Energy use reductions from efficiency improvements may be offset over time by variations in ore grade increases in mining and processing activities. Prominent Hill commenced operation in February 2009. A baseline for energy consumption is being developed to enable our operations team to identify effective efficiency projects to be implemented in the coming years.
Total energy consumption for OZ Minerals was 2.06 petajoules during 2009. Prominent Hill is our major asset and used 2.05 petajoules. Purchased electricity and diesel are the dominant energy sources for Prominent Hill, contributing 35 per cent and 62 per cent, respectively. Electricity for Prominent Hill is purchased from the South Australian electricity grid.
Table A: Total direct and indirect energy consumption 2009 (gigajoules)
| Prominent Hill | Exploration | Group Office | Total | |
|---|---|---|---|---|
| Direct1 | 721,482 | 2,826 | NA | 1,332,606 |
| Indirect2 | 1,329,780 | 55 | 2,183 | 723,720 |
| Total | 2,051,262 | 2,881 | 2,183 | 2,056,327 |
1 Direct energy consumption – resulting from the onsite consumption of fuels and explosives or where electricity is generated.
2 Indirect energy consumption – due to the import of electricity from external parties, commonly the electricity grid.
Greenhouse gas emissions
The group’s total greenhouse gas emissions for 2009 were equivalent to 263,000 tonnes of CO2-e. The majority of greenhouse gas emissions were generated from the use of purchased electricity.
Table B: Total direct and indirect greenhouse gas emissions 2009
| Greenhouse gas emissions (CO2-e t) |
Prominent Hill | Exploration | Group Office | Total |
|---|---|---|---|---|
| Direct1 GHG Emissions | 93,804 | 66 | NA | 94,610 |
| Indirect2 GHG Emissions | 168,346 | 196 | 740 | 168,542 |
| Total | 262,149 | 263 | 740 | 263,152 |
1 Direct greenhouse gas emissions – resulting from the onsite consumption of fuels and explosives or where electricity is generated.
2 Indirect greenhouse gas emissions – due to the import of electricity from external parties, commonly the electricity grid.
Due to Prominent Hill beginning full operation in February 2009, there is currently no baseline which to compare energy efficiency improvement for the site.
